require 'digest/sha1'
class User < ActiveRecord::Base
  # Virtual attribute for the unencrypted password
  attr_accessor :password
  
  # ACL FEATURES
  has_many :permissions, :dependent => :delete_all
  has_many :roles, :through => :permissions
  
  # USER ICON FEATURES
  has_one :user_photo, :dependent => :delete
  
  # Change this path to point to the location of the default user photos
  DEFAULT_PHOTO_PATHS = {:small => "/defaults/user_small.png",
                         :normal => "/defaults/user_normal.png",
                         :medium => "/defaults/user_medium.png",
                         :large => "/defaults/user_large.png"}
  
  # AUTHOR OF FEATURES FOR MODELS THAT ACT AS AUTHORED
  has_many :authorings
  
  # STANDARD USER MODEL
  validates_presence_of     :name, :email
  validates_presence_of     :password,                   :if => :password_required?
  validates_presence_of     :password_confirmation,      :if => :password_required?
  validates_length_of       :password, :within => 4..40, :if => :password_required?
  validates_confirmation_of :password,                   :if => :password_required?
  validates_length_of       :name,    :within => 3..40
  validates_length_of       :email,    :within => 3..100
  validates_uniqueness_of   :name, :email, :case_sensitive => false
  before_save :encrypt_password
  
  def to_s
    name
  end
  
  def authored
    authorings.collect {|authoring| authoring.authored}
  end

  # Authenticates a user by their name name and unencrypted password.  Returns the user or nil.
  def self.authenticate(email, password)
    u = find_by_email(email) # need to get the salt
    u && u.authenticated?(password) ? u : nil
  end

  # Encrypts some data with the salt.
  def self.encrypt(password, salt)
    Digest::SHA1.hexdigest("--#{salt}--#{password}--")
  end

  # Encrypts the password with the user salt
  def encrypt(password)
    self.class.encrypt(password, salt)
  end

  def authenticated?(password)
    crypted_password == encrypt(password)
  end

  def remember_token?
    remember_token_expires_at && Time.now.utc < remember_token_expires_at 
  end

  # These create and unset the fields required for remembering users between browser closes
  def remember_me
    self.remember_token_expires_at = 2.weeks.from_now.utc
    self.remember_token            = encrypt("#{email}--#{remember_token_expires_at}")
    save(false)
  end

  def forget_me
    self.remember_token_expires_at = nil
    self.remember_token            = nil
    save(false)
  end
  
  # USER PHOTO ACCESSORS
  def photo=(file_data)
    if file_data != ""
      @photo = UserPhoto.new(:uploaded_data => file_data);
      if !self.user_photo.nil?
        self.user_photo.destroy
      end
      @photo.save
      self.user_photo = @photo
    end
  end
  
  def photo(size=:normal)
    if use_default_photo || self.user_photo.nil?
      DEFAULT_PHOTO_PATHS[size]
    else
      self.user_photo.public_filename(size)
    end
  end

  protected
    # before filter 
    def encrypt_password
      return if password.blank?
      self.salt = Digest::SHA1.hexdigest("--#{Time.now.to_s}--#{name}--") if new_record?
      self.crypted_password = encrypt(password)
    end
    
    def password_required?
      crypted_password.blank? || !password.blank?
    end
end
